EXCESSIVE RAINFALL DISCUSSION
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
919 PM EDT WED APR 20 2011
 
...VALID 03Z THU APR 21 2011 - 00Z FRI APR 22 2011...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...

SLIGHT RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
20 N GWO 45 NNE GLH 20 SE PBF 25 SW PBF 20 SSE M89 25 SE DEQ
25 NNE LBR 45 WNW DEQ 20 SE RKR 30 NW LRF NQA 45 SSE MKL
45 WNW MSL 20 WSW DCU 15 NNE BHM 30 ENE TCL 15 S GTR 15 E GWO
20 N GWO.
 
EXTREME SE OK TO CNTRL AND NRN MS/AL...

THUNDERSTORMS WERE BECOMING ALIGNED ALONG AN EAST TO WEST LINE
OVER PARTS OF EASTERN AR INTO NORTHERN MS AS OF EARLY WEDNESDAY
EVENING.  THE AREA WAS MOVING VERY SLOWLY NORTHWARD WHILE
INDIVIDUAL CELLS WERE MOVING EAST.  THIS WAS SETTING UP SOME
TRAINING OF CELLS THAT WERE PRODUCING HEAVY RAINFALL OVER AREAS
THAT HAD ALREADY RECEIVED 1 TO 1.5 INCHES OF RAIN EARLIER IN THE
DAY. AS A RESULT...WE EXPANDED THE SLIGHT RISK NORTH A BIT AND
EXTENDED THE WESTERN BOUNDARY BACK INTO EXTREME SOUTHEAST OK. 
WHILE MOST OF THE RAIN APPEARS TO BE FOCUSED NORTH OF
WEBSTER/MONTGOMERY/OKTIBBEH AND CHOCTAW COUNTIES IN MS...WE OPTED
TO KEEP THE SLIGHT RISK IN THE AREA GIVEN POTENTIAL FOR ADDITIONAL
CONVECTION TO OCCUR OVER AN AREA OF LOW FFG. 

00Z UPPER AIR SHOWED THE AXIS OF MAXIMUM PWS OVER E TX INTO THE
EXTREME SOUTHEAST CORNER OF OK.  WIND PROFILERS SHOW LOW LEVEL
FLOW BECOMING MORE SOUTHERLY AND STRENGTHENING...SUGGESTING THAT
CONVECTION OVER THE AREA WILL HAVE AMPLE MOISTURE THROUGHOUT THE
NIGHT. 

BANN
$$